Algae have recently been in the news as a possible source of bio-fuels that may offer a replacement for fossil fuel. Indeed, with the recent soaring oil prices seen in 2008 and the grim numbers for proven oil reserves and projected oil reserves, bio-fuels are ever more frequently looked at as a necessary replacement for fossil fuels. However, most bio-fuel production competes with world food production, for example when bio-diesel is derived from crops such as rapeseed, corn, soybeans and the like. Thus, the most recent search for bio-fuel replacement of fossil fuel has turned to algae sources rather than food crops. Algae are well known for their fast growth rates, reaching 200 tons of algae mass per acre, which are at least one to two magnitudes higher than typical food-source plants. Most exciting is that growing algae in “bio-reactors” offers a method for scrubbing CO2 from manufacturing plant effluent gas, and in this way the CO2 that would ordinarily have gone straight into the atmosphere is re-routed to algae photosynthesis and reproduction. For example, U.S. Patent Application Publication 2007/0289206 (Kertz) presents a process and device for sequestering CO2 using algae. The process utilizes a plurality of vertically suspended bioreactors to maximize efficiency of the photosynthesis reaction.
Through photosynthesis with CO2 consumption, many species of algae produce and/or store a rich selection of bioorganic molecules including triglycerides, cellulose, alginates, agar carrageenan, sugars, glycoproteins, chlorophyll, astaxanthin, and a host of others. Many of these materials are used in industry directly (industrial gums such as agar, alginates and carrageenan) whereas others are in the spotlight as precursors to bio-fuel (particularly the lipids for algae-oil, and cellulose for subsequent hydrolysis and fermentation to ethanol).
Selection of algae species (natural and/or bioengineered, autotrophic or heterotrophic), and their growth conditions, together provide control in the variety of bioorganic materials available from the algae. These bioorganic materials may be extracted from the dried “algae mass”, or may be found intracellularly or extracellularly stored, or even excreted as metabolites. For example, many companies continue to explore the dependence of both algae species and growth conditions on lipid yield. Generally speaking, algae appear to produce more highly unsaturated fiats than, animal or vegetable sources, similar to what is seen with other marine sources such as fish oil, and green algae appear best for shorter carbon chain lipid production. Additionally, some diatoms (kontophyta) are known to produce intracellular lipids. It appears that when some diatom species are raised in conditions of silica deprivation, sinking rates increase, and that in turn appears to trigger increased lipid production as a way to restore buoyancy.
Some algae and diatom species are known to produce more protein, carbohydrate and even hydrocarbon than lipids. For example, Botryococcus is a well known hydrocarbon producer where the bulk of its hydrocarbon is extracellularly located in the colony's matrix and in occluded globules. Some unique species of cyanobacteria (blue-green algae) have now been discovered by University of Texas-Austin researchers to continuously produce glucose, cellulose and sucrose as metabolites, thus obviating the need to destroy the organisms to harvest the useful bioorganic substances.
“Algae Extracts”, which are often referred to as “Algae Colloid”, are the chemicals directly extracted from blue, green and red algae through chemical or physical approaches. They are widely applied as food ingredients for human health and medical benefits, in cosmetic, household and personal care industry, some of those “Algae Extracts” such as carrageenan, a gelatinous material derived from Chondrus crispus and other species of red algae, is widely used as a thickening, stabilizing, emulsifying or suspending agent. Additionally, some species of dried marine micro-algae (e.g., Schizochytrium sp.) which is rich in the omega-3 long chain polyunsaturated fatty acid DHA (docosahexaenoic acid) is used as a food ingredient and supplement.
The prior art literature teaches methods of obtaining bioorganic substances from algae feedstock, with the end purpose of producing bio-fuels from the triglycerides or the saccharidic materials. In general, lipids may be extracted from algae and diatoms much in the same way oils are extracted from vegetative sources. That is, algae may be simply pressed, expeller pressed, solvent extracted (e.g., hexane), pressed then solvent extracted, critical fluid extracted, or in processes unique for algae, subjected to osmotic, sonicative or even enzymatic rupture of their cell walls in order to collect the lipids produced. Enzymatic processes may also be used on wet algae or dried algal mass to liberate cellulose, sugars and other bioorganic substances.
For example, U.S. Pat. No. 7,351,558 (Ruecker, et al.) claims a method for extracting lipids from algae species such as Thraustochytrium and Schizochytrium without the use of organic solvents. The patented method involves lysing the cells and a simple separation process.
Additionally, U.S. Patent Application Publication 2008/0160593 (Oyler) teaches a process for high-yielding micro-algae oil production comprising sequential photoautotrophic and heterotrophic reactions, followed by extraction of algae oil from the algae via a biological process. The Oyler application also teaches different routes of converting algae to algae lipid, and subsequently the algae lipid to bio-diesel, along with routes to convert algae to starch and cellulose and then ultimately to sugar.
U.S. Patent Application Publication 2008/0155888 (Vick, et al.) teaches the use of a mano-material to enhance the lipid oil extraction and purification from the crude biomass extract.
Finally, U.S. Pat. No. 7,135,308 and Application Publication 2007/0202582 (Bush, et al.) teach a process for the production of ethanol through fermentation of algae biomass in the presence of yeast.
Interestingly enough, the literature scantly mentions bio-derived chemicals, such as specialty chemicals, for non-food uses, where the organisms of origin are algae and where the biochemicals are not precursors intended for bio-fuel. The most relevant examples include U.S. Patent Application Publication 2008/0103340 (Binder, et al.) that teaches a process for producing bio-derived propylene glycol and ethylene glycol via hydrogenolysis along with an analytical test based on C12/C13 isotope ratio that may be used to substantiate that these materials are bio-derived.
Even more scant are references that teach non-food/non-fuel uses of bio-derived specialty chemicals. Of these few references, the most relevant is U.S. Patent Application Publication 2007/0202126 (Joerger et al.) that teaches botanical extracts, vegetal extracts, protein extracts, lipid extracts, marine extracts, algae extracts and milk extracts that are each combined with bio-derived 1,3-propane diol (“Bio-PDO”) and/or an ester of Bio-PDO.
The references above and public knowledge in the field of algae research do not teach non-food, non-fuel consumer product formulations incorporating algae-derived functional ingredients and precursors obtained through autotrophic and/or heterotrophic processes. The published references do not teach the art of synergistically incorporating specific algae derived ingredients and specialty chemicals synthesized from algae precursors to create consumer products with superior properties in the areas of personal care (skin care and hair care), household care (hard surface cleaning, etc.), and fabric care.